NON GSTP

Nothing like that Sir

please note that if non GSTP doing GST work for any organisation or any other person is assume that all the work are are done by the organisation. in that case gstp not work legally.
whenever the filling of return is assumed that organisation file his / her return self. here no role of gstp. GST department assume that such organisation work self or any legal consultant like c.a , icwai. etc. because the GSTP details are not submit by the organisation.

Where is it said in the law that the work done by a person other than GSTP is not legal? kindly share it. And then, FYI eventhough returns are filed by GSTPs, the taxpayer will be responsible for the returns filed on behalf of him and not the GSTP who files it. Even in erstwhile VAT scheme there was similar framework for STPs. But all accountants who filed returns were not STPs. All these GSTP, STP, TRP are to my knowledge just additional and not mandatory.